Prepositions of Time - Teoría

The prepositions of time for and since are both used to describe intervals of time but are used in different ways.

For

We use for to indicate how long a state or event lasts:
I was at Southampton University for five years.
I've had toothache for three days now.

Since

We use since to indicate the starting point of a state or event:
I've been in Santander since 1988. I've head a headache since Tuesday.

Remember!

Since is normally used with perfect tenses (perfect simple and continuous), but sometimes it is also used with present or past tenses:
Since the divorce he can't stop feeling guilty.
Since he received his exam results he thinks he's a genius.

Learning tip

Write three pairs of sentences about things you've been doing recently. In each pair use for in one sentence and since in the other.
For example: I've been up since 7:00./I've been up for 5 hours.

There are several prepositions of time that indicate intervals:

In indicates the end of a period starting from now:
Your car will be ready in two days.
I'll be with you in a second.

For indicates how long something lasts:
He's been running for half an hour - he must be tired now.

During indicates when something happens within a particular period of time:
She phoned him several times during the afternoon.
He consistently interrupted her during her speech.

Over, (all) through, throughout, all mean 'during the whole of a period of time':
Throughout the war food was very scarce
Over the last few days it hasn't stopped raining.

From ... to/until/up to indicates the whole period between the start point and the end point:
We played football from 10 in the morning until 9 at night.

Between ... and indicates a point or period (not the entire time) within the start point and the end point:
I'll get there sometime between 8 and 9.

By has a couple of meanings.
- It can mean 'no later than':
I'll get there by 4.
- It can also mean 'progress up to a specific time':
By the end of the meal everyone was full.
- By the time is a common phrase which means 'when' or not later than the moment that something happens:
By the time I got there the match had started.
By the time the film starts I'll be in bed.

Remember!

Sometimes more than one preposition is grammatically possible, but the meaning is different:
He'll be in Valencia in a week. (= a week from now)
He'll be in Valencia for a week. (= she'll spend a week there sometime in the future)
We were in Bath during the summer. (= we spent an unspecified period in Bath within that summer)
We were in Bath throughout the summer. (= we spent the summer in Bath)
I will be there from Monday to Sunday. (= for the whole week)
I will be there between Monday and Sunday. (= sometime during that week)

Learning tip

Write a paragraph about your activities last week using as many of the prepositions of time from this unit as possible.
For example: Last Friday, I went shopping from 10.00 to 2.00. During that time, I saw three friends and had a beer with my brother.

Prepositions of time are used to describe different points and periods of time.

At is used to indicate points in time or holiday periods:
I'll be there at 5.
He's leaving at lunchtime.
What are you doing at Christmas? (= during the Christmas holidays, not just on Christmas day)

On is used to indicate specific days:
The holiday starts on Tuesday.
My birthday is on 21 March.

In is used to indicate periods that are shorter or longer than a day:
We're going out in the afternoon.
She takes her holidays in July.
They met in 1997.
Note the use of at with night:
They never go out at night. (= in the evening)

We use by in the expressions by day and by night to mean during the day/night:
He works by night and sleeps by day.

No preposition

We don't use prepositions with time adverbs (yesterday, today, etc.) and with determiners (last, next, some, this, etc.):
I've been working all week.
I saw him yesterday.
He'll be leaving next month.
They're going to Amsterdam next Thursday.

Remember!

When we mention a specific day we use on (not in) even if it is for only part of the day:
We're going to the cinema on Friday evening.

Note the expression on the hour:
Trains to Edinburgh leave on the hour. (= at 1 o'clock, at 2 o'clock, etc.)

Learning tip

Choose a memorable event in your life and write a paragraph with the time details, using as many of the prepositions above as possible.
For example: Last month I celebrated my birthday. My birthday is on 12th March, but I had the party on the 15th March because I wanted to celebrate at the weekend.

Some prepositions of time indicate the position of a moment or event in relation to another moment or event.

The most common ones are before, after, till/until and since:

Before indicates a point in time that precedes another one:
We saw Simon before he went to hospital, and he looked very ill.

After indicates a point in time that follows another one:
We saw Jane after she had a haircut, and her hair was very short.

Till/until indicates the end of a state or action:
I'll be out until four o'clock.
I'll stay till dinnertime.

Since indicates the beginning of a state or action in the past:
I've been here since three o'clock.
She's been here since breakfast time.

When the starting point is in the future we use from. Compare:
I've been here since 5 o'clock. I'll be there from 5 o'clock.

Remember!

Till and until mean exactly the same thing. In American English till is often spelt til.

Learning tip

Write a paragraph about somebody you know/admire using as many of the prepositions of time from this unit as you can.
For example: I have known John since I was at university. We shared a flat together for three years. After university he moved to Brighton and I didn't see him again until 2008.